Encouraging cancer survivors to discuss clinical trials with their physicians may increase enrollment in clinical trials. Health messages offer one method for encouraging such discussions. We hypothesized that matching messages to an individual's preference for detailed or non-detailed information (i.e., monitoring style) would result in more discussions. Participants (N = 538) were cancer survivors, who phoned the National Cancer Institute's Cancer Information Service (CIS). Participants were classified as higher or lower monitors and then randomized to receive detailed or non-detailed messages in the mail 1 and 4 weeks following their baseline CIS call. At 12 weeks, there was a significant interaction between monitoring style and message detail. Follow-up analyses were nonsignificant but suggested a theoretically consistent pattern in which non-detailed messages were more effective among lower monitors. These findings imply that providing extremely detailed information may be excessive, even to individuals engaged in information seeking behavior.